Mitsubishi says both its president and vice president will vacate their positions next month in response to the Japanese automaker's widening fuel economy scandal.

President Tetsuro Aikawa and Vice President Ryugo Nakao will step down on June 24 over what the automaker says was a work environment that increasingly supported fraudulent activities regarding fuel economy reporting in order to meet domestic and global standards..

Aikawa said he will ask Mitsubishi's new steward, Nissan, to appoint its own executives in charge of vehicle development. Nissan is set to invest about $2.17 billion into taking a controlling share in long-struggling Mitsubishi.

This drama started when Mitsubishi came under fire recently for overstating fuel economy on several vehicles by as much as 15 percent in order to meet targets. Initial reports suggested only a pair of Kei cars—ultra-small city cars that qualify for takes breaks in Japan—were affected, but the automaker has more recently admitted that fuel economy for the plug-in version of the Outlander and versions of the RVR, which is sold in the U.S. as the Outlander Sport, was also reported incorrectly.

Nissan has indicated that it hopes to turn Mitsubishi around, but the task is daunting. Mitsubishi's aging lineup and a culture that even the automaker itself admits has been problematic, may take years to correct.